Electric vehicles that run on driving power of electric motors and hybrid vehicles that run on the driving power of both internal combustion engines and electric motors are each mounted with a battery module, as its power source device, in which a large number of batteries are provided. A battery module is housed in a casing in a state of retaining a plurality of batteries by a holder. A space through which air can flow is formed inside of the casing so as to cool the batteries. The batteries are arranged vertically in the space inside the casing in a state where they are fitted into retaining holes formed in the holder. Intervals between the respective batteries are retained to be constant, and the respective batteries are cooled by circulating the air in the intervals.
To produce the battery module at low cost, there is a desire to place the plurality of batteries simultaneously in the space in the casing and position them. However, when a plurality of batteries is inserted into the space in the casing at one time, the respective batteries may be inserted into the casing with being tilted, and variations may be generated in positions of the batteries and postures of the batteries after the insertion, by the postures of the batteries after the insertion becomes tilted for example.
Further, as a method for positioning batteries to a casing, for example, as disclosed in JP 2014-2850 A and JP 2009-272160 A, there is a method for positioning the batteries by forming tapered portions on inner circumferential surfaces of retaining holes that retain the batteries in the holder.